Method for arranging frame structure of flexible short TTI according to change in control region, and device using same
Provided are a method and a device for arranging a subframe structure of a short TTI according to the change in a control region in a wireless communication system. Specifically, a plurality of first downlink channels received during an sTTI and a second downlink channel received during a TTI are received. The number of symbols used for each of the plurality of first downlink channels is determined by a format indicator channel included in the first symbol of a subframe. Further, the plurality of first downlink channels are demodulated by using scheduling information included in each of the plurality of first downlink channels, and the second downlink channel is demodulated by using scheduling information included in a control region indicated by the format indicator channel.
1. A method of performing communication by using a plurality of control channels and a plurality of data channels delivered through a plurality of symbols in a wireless communication system, the method comprising:
receiving a plurality of first downlink channels comprised in a subframe corresponding to one transmission time interval (TTI) and received during a short TTI (sTTI), and receiving a second downlink channel received during the TTI, wherein the number of symbols used for each of the plurality of first downlink channels is determined on the basis of a format indicator channel comprised in a first symbol of the subframe and the plurality of first downlink channels are sequentially received; and
demodulating the plurality of first downlink channels by using scheduling information comprised in each of the plurality of first downlink channels, and demodulating the second downlink channel by using scheduling information comprised in a control region indicated by the format indicator channel.
2. The method of claim 1 , wherein each of the plurality of first downlink channels comprises a short physical downlink shared channel (sPDSCH), the second downlink channel comprises a physical downlink shared channel (PDSCH), a first symbol of each of the plurality of first downlink channels comprises a short physical downlink control channel (sPDCCH) for the sPDSCH, and a control region of the second downlink channel comprises a PDCCH for the PDSCH.
3. The method of claim 2 , wherein the number of symbols used for each of the plurality of first downlink channels is determined on the basis of the number of symbols used in the control region.
4. The method of claim 2 , wherein the sPDSCH and the PDSCH are received in different frequency bands.
5. The method of claim 1 , wherein the scheduling information comprised in each of the plurality of first downlink channels is comprised in a first symbol of the plurality of first downlink channels.
6. The method of claim 1 , wherein the scheduling information for the first downlink channel received first among the plurality of first downlink channels is comprised in the control region.
7. The method of claim 1 , wherein the symbol is an orthogonal frequency division multiplexing (OFDM) symbol or a single-carrier frequency division multiple access (SC-FDMA) symbol.
8. The method of claim 1 , wherein a user specific (UE)-reference signal (RS) is comprised only in one symbol of each of the plurality of first downlink channels.
9. The method of claim 8 , wherein the UE-specific RS comprises a first RS sequence to which a first orthogonal sequence is applied and which is used for a first antenna, and a second RS sequence to which a second orthogonal sequence is applied and which is used for a second antenna.
10. The method of claim 9 , wherein the first orthogonal sequence and the second orthogonal sequence are selected from among mutually orthogonal walsh codes.
11. A user equipment (UE) for performing communication by using a plurality of control channels and a plurality of data channels delivered through a plurality of symbols in a wireless communication system, the UE comprises:
a radio frequency (RF) unit for transmitting and receiving a radio signal; and
a processor operatively coupled to the RF unit, wherein the processor is configured to:
receive a plurality of first downlink channels comprised in a subframe corresponding to one transmission time interval (TTI) and received during a short TTI (sTTI), and receive a second downlink channel received during the TTI, wherein the number of symbols used for each of the plurality of first downlink channels is determined on the basis of a format indicator channel comprised in a first symbol of the subframe and the plurality of first downlink channels are sequentially received; and
demodulate the plurality of first downlink channels by using scheduling information comprised in each of the plurality of first downlink channels, and demodulate the second downlink channel by using scheduling information comprised in a control region indicated by the format indicator channel.